UltraMaxx is the trade name of a revolutionary new convertible top developed by GAHH Automotive. Incorporating a patent pending method for the installation of the window, UltraMaxx virtually eliminates window separation and leaks. The process is so reliable GAHH is able to offer a LIFETIME WARRANTY. The UltraMaxx manufacturing system also eliminates the stitching, piping and pressmarks commonly found around the window on all aftermarket tops.

GAHH UltraMaxx Window


"UltraMaxx, the best built, best looking tops available today!"


In the early days, when convertible tops were only available with plastic windows, installation of the window was easy….simply sew the plastic into the topping material.


However, with the advent of glass window tops things got more complicated. Sewing was out of the question so a method of adhering or “gluing” the topping to the glass was required. This was very difficult because glass, due to its inherent nature does not want to stick to anything and topping material is engineered to repel everything that tries to stick to it.


Several methods of installation were developed but eventually most car manufacturers adopted a process called “heat sealing”. This involves placing a plastic tape between the glass and the topping. The assembly is then placed in a molded press and electricity is applied until it heats the tape to a point where it melts, “sealing” the glass to the topping.


The unpredictability of this process results in a high failure rate of the bond. Occurring over time, this failure can result in the window completely falling out of the top or it may fail only to the point of leaking water into the car.


Typical Heat Sealed Window
Heat Sealed Window With Piping and Stitching

When the aftermarket manufacturers of convertible tops began to produce glass window tops most chose to use the heat seal method developed by the OEM’s. They, like the OEM’s, continue to have mixed results with this process and failures still occur on a regular basis.


Some aftermarket manufacturers, due to the cost and complexity of the heat seal process, use adhesive or “silicone” to stick the windows into the topping. A process prone to be even less reliable then heat seal. Several years ago, GAHH Automotive decided that a better method of installing glass windows was required.


Our engineering team set out to develop a process that would address the problems of separation and leakage with a side benefit of a more “factory finished” look. After 1000's of hours of researching, prototyping and testing, GAHH has developed a new patent pending process that virtually eliminates all of the inherent problems of heat seal or silicone.


This process is so unique that completely automated equipment also had to be designed in order to manufacture the tops. While the actual process is complicated and proprietary we can say that it involves wrapping the topping around an internal support structure and adhering the glass to the resulting assembly with a special bonding agent developed specifically for this purpose. The result is an extremely strong bond between the glass and the topping with no stitching or piping.


Trademarked as UltraMaxx, these tops have set a new standard in the industry.